How to populate value with input - json

Question

From a composer.lock I am creating json output of some fields, like this:
<composer.lock jq '.packages[] | {site: "foo", name: .name, version: .version, type: .type}' | jq -s
It works fine:
{
"site": "foo",
"name": "webmozart/path-util",
"version": "2.3.0",
"type": "library"
},
{
"site": "foo",
"name": "webonyx/graphql-php",
"version": "v14.9.0",
"type": "library"
}
but now I want to add a generated value, using uuidgen, but I can't figure out how to do that.
End result would be something like:
{
"site": "foo",
"name": "webmozart/path-util",
"version": "2.3.0",
"type": "library",
"uuid": "c4e97c3c-147d-4360-a601-6b4f6f5e71bb"
},
{
"site": "foo",
"name": "webonyx/graphql-php",
"version": "v14.9.0",
"type": "library",
"uuid": "6fbe472b-49fe-4064-93f0-09a18a7e1c24"
}
I think I should use input, but all I tried so far have failed.

Answer 1

If your shell supports process substitution, you can avoid a two-pass solution as follows:
jq -nR --argfile input composer.lock '
$input
| .packages[]
| {site: "foo", name: .name, version: .version, type: .type, id: input}
' < <(while true; do uuidgen; done)
The point here is that by using process substitution as above, the termination of the "consumer" (jq) will also terminate the "producer" of UUIDs.

Answer 2

Here's one possibility that does not require your shell to support "process substitution" but which entails two passes, the first for determining the number of UUIDs that are required:
# Syntax: generate N
function generate {
for ((i=0; i<$1; i++)) ; do
uuidgen
done
}
generate $( <composer.lock jq '.packages|length') |
jq -nR --argfile input composer.lock '
($input
| .packages[]
| {site: "foo", name: .name, version: .version, type: .type,
id: input})'